“Our study adds to the accumulating evidence of the health benefits of moderate chocolate intake and highlights the importance of behavioral factors for potentially lowering the risk of arrhythmias,” added Dr. Elizabeth Mostofsky, the study’s lead author and an instructor in the Department of Epidemiology at Harvard T. H. Chan School of Public Health.

There have been a lot of studies that point out how cocoa and cocoa-containing food items, in particular, dark chocolate, can improve cardiovascular health. This benefit, according to researchers, could be linked to the high flavanol content of cocoa, which is known to promote healthy blood vessels. However, there isn’t that much data on the link between chocolate consumption and AFib – a condition which affects at least 2.7 million people in the U.S. alone.

The American Heart Association defines AFib as “a quivering or irregular heartbeat (arrhythmia) that can lead to blood clots, stroke, heart failure and other heart-related complications.” However, only 33 percent of AFib patients think that it is a serious condition, despite the increased risk for stroke and heart-related deaths. In addition cases of AFib also can result in strokes, cognitive decline, and dementia in the long run.

Researchers looked at over 55,000 adults who participated in the Danish Diet, Cancer, and Health Study. Information on the participants’ body mass index (BMI), blood pressure, and cholesterol, which were previously measured when they were recruited between 1993 and 1997, were collected by the researchers. They gleaned additional data from the participants using questionnaires to determine their health conditions, including cases of high blood pressure, diabetes, or cardiovascular diseases (CVD), as well as information on their lifestyle and diet – in particular, their daily chocolate intake. The researchers then tracked the participants for over 13 years, where they found that those who ate chocolates weekly significantly reduced their AFib risk by at least 20 percent, with similar results posted for both male and female participants.

However, this doesn’t mean that people should start gorging on chocolate: According to the researchers, eating more than six servings of chocolate in a week tends to cancel out its positive effects.

There’s regular chocolate, then there’s dark chocolate

Of course, this study adds to a growing body of proof on the health benefits of cocoa, especially against CVD. However, this doesn’t mean that all types of chocolate, in general, are good for you. Regular chocolate – the store-bought, saccharine kind – is loaded with calories and added sugar, making it easy to overeat.

Dark chocolate, on the other hand, is packed with nutrients that can improve a person’s health. In particular, studies have shown that dark chocolate, and not regular chocolate, has a high antioxidant content and can lower the risk of heart disease. That’s on top of its slightly bitter yet velvety taste.

For one, it’s packed with soluble fiber and minerals. In a 100-gram bar (around 3.5 ounces) of dark chocolate with a 70 to 85 percent cocoa content, it contains almost half the recommended daily allowances (RDA) for iron, magnesium, copper, and manganese. Studies have also shown that the flavonols in dark chocolate can induce the production of nitric oxide, a chemical which regulates the constriction of arteries and lowers its resistance to blood flow.

It also raises a person’s HDL (good cholesterol) profile and reduces insulin resistance, making it beneficial not only for CVD but also diabetes. The bioactive compounds in dark chocolate also increase the skin’s density and hydration, improving its blood flow and protecting it against sun-induced damage.